Conventional hand tools, such as hammers, hatchets, and similar swingable implements, were typically provided with a linear shaft for providing mechanical advantage. Those handles relied primarily upon a frictional hand gripping action with the hand being held between defined boundaries for optimum performance. In addition, the previously available handles that were intended for impact driving required a tight-fisted grip with the handle being swung in an arcuate motion about the user's wrist.
A problem with those tool handle designs was that it was difficult to control movement of the tool head with accuracy and precision during the power stroke. This could be compensated for by using differently shaped and weighted tool heads to customize the tools for the particular applications.
A further disadvantage of the prior tool handle arrangements was that the firmness of the gripping action was primarily a factor of the compressive forces applied through the muscular hand-grip of the user. It should also be apparent that the shock effect upon impact was transmitted through the hand, arm and body of the user and furthermore, that the hand grip could be subject to slippage during use.
Another shortcoming of the aforementioned handle designs was that the free end of the handle could not be utilized as an alternate power grip or as a fulcrum for delivering a pendulum motion driving force.
A further deficiency of the aforementioned tool handles was that, under actual field conditions as when using the hand tool within close proximity to a working surface, the user's fingers frequently projected beyond the periphery of the handle margin and this often resulted in "skinned" knuckles.
Previous attempts to modify tool handles included the incorporation of finger recesses, as were shown in U.S. Pat. Nos. 2,076,836, 2,124,615 and 2,205,769 and in U.S. Pat. Nos. Des. 139,475, Des. 157,883 and Des. 185,675. Those patents, however, did not present a handle body with finger interaction for generating a power stroke using pivotal action about a selected finger.
The instant invention overcomes many of the problems, disadvantages and drawbacks of the prior art and provides a handfitting handle body adapted for driving an impact head and for achieving increased accuracy and precision, improved directional and power control, and reduced hand slippage.